Transmitting apparatus, receiving apparatus, and control methods thereof

ABSTRACT

A transmitting apparatus is provided. The transmitting apparatus includes: an L1 signaling generator configured to generate L1 signaling including first information and second information; a frame generator configured to generate a frame including a payload including a plurality of sub frames; and a signal processor configured to insert a preamble including the L1 signaling in the frame and transmit the frame. The first information includes information required for decoding a first sub frame among the plurality of sub frames. Therefore, a processing delay in a receiving apparatus is reduced.

CROSS-REFERENCE TO THE RELATED APPLICATIONS

This is a Continuation of U.S. application Ser. No. 16/292,215 filedMar. 4, 2019, which is a Continuation of U.S. patent application Ser.No. 15/959,484 filed Apr. 23, 2018, which is a Continuation of U.S.patent application Ser. No. 15/217,241 filed Jul. 22, 2016, issued asU.S. Pat. No. 9,954,917 on Apr. 24, 2018, which claims priority fromU.S. Provisional Patent Application No. 62/195,883, filed on Jul. 23,2015, in the United States Patent and Trademark Office, and KoreanPatent Application No. 10-2016-0087975, filed on Jul. 12, 2016, in theKorean Intellectual Property Office, the disclosures of which areincorporated herein by references in their entirety.

BACKGROUND 1. Field of the Invention

Apparatuses and methods consistent with the exemplary embodiments of thepresent inventive concept relate to a transmitting apparatus, areceiving apparatus, and control methods thereof, and more particularly,to a transmitting apparatus that maps data onto at least one signalprocessing path and transmits the mapped data, a receiving apparatus,and control methods thereof.

2. Description of the Related Art

In the information-oriented society of the 21st century, broadcastingcommunication services are entering an era of digitization,multi-channel, broadband, and high quality. In particular, ashigh-quality digital televisions (TVs), portable multimedia players(PMP), and portable broadcasting apparatuses have been increasingly usedin recent years, even in digital broadcasting services, a demand forsupporting various receiving methods has been increased.

Thus, the broadcasting communication standard group has establishedvarious standards according to demands to provide various services tosatisfy user's needs. Still, however, it is required to find methods forproviding better services having improved performance.

SUMMARY

Exemplary embodiments of the inventive concept may overcome the abovedisadvantages and other disadvantages not described above. Also, theexemplary embodiments of the inventive concept are not required toovercome the disadvantages described above, and may not overcome any ofthe problems described above.

The exemplary embodiments provide a transmitting apparatus that providesa preamble including various types of information, a receivingapparatus, and control methods thereof.

According to an exemplary embodiment, there is provided a transmittingapparatus which may include: an L1 signaling generator configured togenerate L1 signaling including first information and secondinformation; a frame generator configured to generate a frame includinga payload including a plurality of sub frames; and a signal processorconfigured to insert a preamble including the L1 signaling in the frameand transmit the frame. The first information may include informationrequired for decoding a first sub frame among the plurality of subframes.

According to an exemplary embodiment, there is provided a receivingapparatus which may include: a receiver configured to receive a frameincluding a preamble including L1 signaling including first informationand second information and a payload including a plurality of subframes; and a signal processor configured to signal-process the frame.The first information may include information required for decoding afirst sub frame of the plurality of sub frames, and the signal processormay decode the first sub frame based on the information included in thefirst information and decode the second information in parallel with thedecoding the first sub frame.

According to an exemplary embodiment, there is provided a method ofcontrolling a transmitting apparatus. The method may include: generatingL1 signaling including first information and second information;generating a frame including a payload including a plurality of subframes; and inserting a preamble including the L1 signaling in the frameand transmitting the frame. The first information may includeinformation for decoding a first sub frame of the plurality of subframes.

According to an exemplary embodiment, there is provided a method ofcontrolling a receiving apparatus. The method may include: receiving aframe including a preamble including L1 signaling including firstinformation and second information and a payload including a pluralityof sub frames; and signal-processing the frame. The signal-processing ofthe frame may include decoding a first sub frame based on informationincluded in the first information and decoding the second information inparallel with the decoding the first sub frame.

According to various exemplary embodiments, a processing delay in areceiving apparatus may be reduced.

Additional and/or other aspects and advantages of the invention will beset forth in part in the description which follows and, in part, will beobvious from the description, or may be learned by practice of theexemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and/or other aspects of the exemplary embodiments will bedescribed with reference to the accompanying drawings, in which:

FIG. 1 is a diagram illustrating a hierarchical structure of atransmitting system according to an exemplary embodiment;

FIG. 2 is a diagram illustrating a schematic configuration of abroadcasting link layer 1400 according to an exemplary embodiment;

FIG. 3A is a diagram illustrating a schematic configuration of atransmitting system (or a transmitting apparatus) according to anexemplary embodiment;

FIGS. 3B and 3C are diagrams illustrating a multiplexing method,according to exemplary embodiments;

FIG. 4 is a block diagram illustrating a detailed configuration of aninput formatting block of FIG. 3A, according to an exemplary embodiment;

FIGS. 5A and 5B are diagrams illustrating a detailed configuration of abaseband formatting block, according to exemplary embodiments;

FIG. 6 is a block diagram illustrating a configuration of a transmittingapparatus according to an exemplary embodiment of the present invention;

FIG. 7 is a diagram illustrating a configuration of a frame that is abase for describing the exemplary embodiments;

FIG. 8 is a diagram illustrating a detailed configuration of the frameof FIG. 7, according to an exemplary embodiment;

FIG. 9 is a diagram illustrating a start time for decoding a related artpayload;

FIG. 10 is a diagram illustrating a start time for decoding a payloadaccording to an exemplary embodiment;

FIG. 11 is a diagram illustrating information included in L1 basicaccording to an exemplary embodiment;

FIG. 12 is a block diagram illustrating a configuration of a receivingapparatus according to an exemplary embodiment;

FIG. 13 is a detailed block diagram illustrating a signal processor indetail according to an exemplary embodiment;

FIG. 14 is a block diagram illustrating a configuration of a receiveraccording to an exemplary embodiment;

FIG. 15 is a block diagram illustrating a demodulator in more detailaccording to an exemplary embodiment;

FIG. 16 is a flowchart illustrating a brief operation of a receiveruntil an actually selected service is played from a time when a userselects a service according to an exemplary embodiment;

FIG. 17 is a flowchart illustrating a method of controlling atransmitting apparatus according to an exemplary embodiment; and

FIG. 18 is a flowchart illustrating a method of controlling a receivingapparatus according to an exemplary embodiment.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Hereinafter, various exemplary embodiments of the inventive concept willbe described in detail with reference to the accompanying drawings.Further, in the following description, a detailed explanation of knownrelated functions or configurations may be omitted to avoidunnecessarily obscuring the subject matter. In addition, terms to bedescribed below may vary according to a user's and an operator'sintentions, the convention, or the like as terms defined by consideringfunctions. Therefore, the definition may be made according to thecontents throughout this specification.

An apparatus and a method proposed in the exemplary embodiments may be,of course, applied to various communication systems including mobilebroadcasting services including a digital multimedia broadcasting (DMB)service, digital video broadcasting handheld (DVB-H), an advancedtelevision systems committee mobile/handheld (ATSC-M/H) service, anInternet protocol television (IPTV) service, and the like, communicationsystems including a moving picture experts group (MPEG) media transport(MMT) system, an evolved packet system (EPS), a long-term evolution(LTE) mobile communication system, a long-term evolution-advanced(LTE-A) mobile communication system, a high speed downlink packet access(HDSPA) mobile communication system, a high speed uplink packet access(HSUPA) mobile communication system, a 3^(rd) generation projectpartnership 2 (3GPP2) high rate packet data (HRPD) mobile communicationsystem, a 3GPP2 wideband code division multiple access (WCDMA) mobilecommunication system, a 3GPP2 code division multiple access (CDMA)mobile communication system, an Institute of Electrical and ElectronicsEngineers (IEEE) 802.16m communication system, a mobile Internetprotocol (Mobile IP) system, and the like.

FIG. 1 is a diagram illustrating a hierarchical structure of atransmitting system according to an exemplary embodiment.

Referring to FIG. 1, a service includes media data 1000 and signaling1050 for transferring information required to acquire and consume themedia data 1000 at a receiver. The media data 1000 may be encapsulatedin a format suitable for transmission prior to the transmission. Anencapsulation method may follow a Media Processing Unit (MPU) defined inISO/IEC 23008-1 MPEG Media Transport (MMT) or a DASH segment formatdefined in ISO/IEC 23009-1 Dynamic Adaptive Streaming over HTTP (DASH).The media data 1000 and the signaling 1050 are packetized according toan application layer protocol.

FIG. 1 illustrates a case in which an MMT protocol (MMTP) 1110 definedin the MMT and a Real-Time Object Delivery over Unidirectional Transport(ROUTE) protocol 1120 are used as the application layer protocol. Inthis case, a method for notifying information about an applicationprotocol, in which a service is transmitted, by an independent methoddifferent from the application layer protocol is required for thereceiver to know by which application layer protocol the service istransmitted.

A service list table (SLT) 1150 illustrated in FIG. 1 represents orindicates a signaling method and packetizes information about theservice in a table for satisfying the aforementioned object. Detailedcontents of the SLT will be described below. The packetized media dataand the signaling including the SLT are transferred to a broadcastinglink layer 1400 through a user datagram protocol (UDP) 1200 and anInternet protocol (IP) 1300. An example of the broadcasting link layer1400 includes an ATSC 3.0 link-layer protocol (ALP) defined in the ATSC3.0 standard (hereafter, referred to as ‘ATSC 3.0’). The ALP protocolgenerates an ALP packet by using an IP packet as an input, and transfersthe ALP packet to a broadcasting physical layer 1500.

However, according to FIG. 2 to be described below, it is noted that thebroadcasting link layer 1400 does not use only the IP packet 1300including the media data and/or the signaling as the input, and instead,may use an MPEG2-TS packet or general formatted packetized data as theinput. In this case, signaling information required to control thebroadcasting link layer is also transferred to the broadcasting physicallayer 1500 in the form of the ALP packet.

The broadcasting physical layer 1500 generates a physical layer frame bysignal-processing the ALP packet as the input, converts the physicallayer frame into a radio signal, and transmits the radio signal. In thiscase, the broadcasting physical layer 1500 has at least one signalprocessing path. An example of the signal processing path may include aphysical layer pipe (PLP) of ATSC 3.0 or the Digital VideoBroadcasting-Second Generation Terrestrial (DVB-T2) standard, and one ormore services or some of the services may be mapped to the PLP.

FIG. 2 is a diagram illustrating a schematic configuration of thebroadcasting link layer 1400, according to an exemplary embodiment.

Referring to FIG. 2, the input of the broadcasting link layer 1400includes the IP packet 1300, and may further include link layersignaling 1310, an MPEG2-TS packet 1320, and other packetized data 1330.

Input data may be subjected to additional signal processing based on thetype of the input data before ALP packetization 1450. As an example ofthe additional signal processing, the IP packet 1300 may be subjected toan IP header compression process 1410 and the MPEG2-TS packet may besubjected to an overhead reduction process 1420. During the ALPpacketization, input packets may be subjected to dividing and mergingprocesses.

FIG. 3A is a diagram illustrating a schematic configuration of atransmitting system or a transmitting apparatus, according to anexemplary embodiment. According to FIG. 3A, a transmitting system 10000according to the exemplary embodiment may include input formattingblocks 11000 and 11000-1, bit interleaved and coded modulation (BICM)blocks 12000 and 12000-1, framing/interleaving blocks 13000 and 13000-1,and waveform generation blocks 14000 and 14000-1.

The input formatting blocks 11000 and 11000-1 generate a baseband packetfrom an input stream of data to be serviced. Herein, the input streammay be a transport stream (TS), Internet packets (IP) (e.g., IPv4 andIPv6), an MPEG media transport (MMT), a generic stream (GS), genericstream encapsulation (GSE), and the like. For example, an ALP packet maybe generated based on the input stream, and the baseband packet may begenerated based on the generated ALP packet.

The bit interleaved and coded modulation (BICM) blocks 12000 and 12000-1determine an forward error correction (FEC) coding rate and aconstellation order according to an area (fixed PHY frame or mobile PHYframe) to which the data to be serviced will be transmitted, and performencoding and time interleaving. Meanwhile, signaling information aboutthe data to be serviced may be encoded through a separate BICM encoderaccording to user implementation or encoded by sharing a BICM encoderwith the data to be serviced.

The framing/interleaving blocks 13000 and 13000-1 combine thetime-interleaved data with a signaling signal including the signalinginformation to generate a transmission frame.

The waveform generation blocks 14000 and 14000-1 generate an orthogonalfrequency-division multiplexing (OFDM) signal in a time domain for thegenerated transmission frame, modulate the generated OFDM signal into anRF signal, and transmit the RF signal to a receiver.

The transmitting system 10000 according to the exemplary embodimentillustrated in FIG. 3A includes normative blocks marked with a solidline and informative blocks marked with dotted lines. Herein, the blocksmarked with the solid line are normal blocks, and the blocks marked withthe dotted lines are blocks which may be used when informativemultiple-input multiple-output (MIMO) is implemented.

FIGS. 3B and 3C are diagrams illustrating a multiplexing method,according to exemplary embodiments.

FIG. 3B illustrates a block diagram for implementing time divisionmultiplexing (TDM), according to an exemplary embodiment.

A TDM system architecture includes four main blocks (alternatively,parts) of the input formatting block 11000, the BICM block 12000, theframing/interleaving block 13000, and the waveform generation block14000.

Data is input and formatted in the input formatting block 11000 andforward error correction is applied to the data in the BICM block 12000.Next, the data is mapped to a constellation. Subsequently, the data istime and frequency-interleaved in the framing/interleaving block 13000and a frame is generated. Thereafter, an output waveform is generated inthe waveform generation block 14000.

FIG. 3C illustrates a block diagram for implementing layered divisionmultiplexing (LDM), according to an exemplary embodiment.

An LDM system architecture includes several other blocks as comparedwith the TDM system architecture. In detail, two separated inputformatting blocks 11000 and 11000-1 and the BICM blocks 12000 and12000-1 for one of respective layers of the LDM are included in the LDMsystem architecture. The blocks are combined in an LDM injection blockbefore the framing/interleaving block 13000. And, the waveformgeneration block 14000 is similar to the TDM.

FIG. 4 is a block diagram illustrating a detailed configuration of theinput formatting block illustrated in FIG. 3A, according to an exemplaryembodiment.

As illustrated in FIG. 4, the input formatting block 11000 includesthree blocks that control packets distributed to PLPs. In detail, theinput formatting block 11000 includes an encapsulation and compressionblock 11100, a baseband formatting block (alternatively, basebandframing block) 11300, and a scheduler block 11200.

An input stream input to the encapsulation and compression block 11100may be various types. For example, the input stream may be a transportstream (TS), an Internet packets (IP) (e.g., IPv4 and IPv6), an MPEGmedia transport (MMT), a generic stream (GS), a generic streamencapsulation (GSE), and the like.

Packets output from the encapsulation and compression block 11100 becomeALP packets (generic packets) (also referred to as L2 packets). Herein,a format of an ALP packet may be one of the Type Length Value (TLV), theGSE, and the ALP.

The length of each ALP packet is variable. The length of the ALP packetmay be easily extracted from the ALP packet itself without additionalinformation. The maximum length of the ALP packet is 64 kB. The maximumlength of a header of the ALP packet may be 4 bytes. The ALP packet hasa length of integer bytes.

The scheduler block 11200 receives an input stream including theencapsulated ALP packets to form physical layer pipes (PLPs) in abaseband packet form. In the TDM system, only one PLP called a singlePLP (S-PLP) or multiple PLPs (M-PLP) may be used. One service may notuse four or more PLPs. In the LDM system constituted by two layers, onein each layer, that is, two PLPs are used.

The scheduler block 11200 receives the encapsulated ALP packets todesignate how the encapsulated ALP packets are allocated to physicallayer resources. In detail, the scheduler block 11200 designates how thebaseband formatting block 1130 outputs a baseband packet.

A function of the scheduler block 11200 is defined by a data size and atime. A physical layer may transmit some of data in the distributedtime. The scheduler block generates a solution which is suitable interms of a configuration of a physical layer parameter by using inputsand information such as constraints and configuration from anencapsulated data packet, the quality of service metadata for theencapsulated data packet, a system buffer model, and system management.The solution is targets of a configuration and a control parameter whichare usable and an aggregate spectrum.

Meanwhile, an operation of the scheduler block 11200 is constrained to aset of dynamic, quasi-static, and static components. Definition of theconstraint may vary according to user implementation.

Further, a maximum of four PLPs may be used with respect to eachservice. A plurality of services which include a plurality of types ofinterleaving blocks may be implemented by up to a maximum of 64 PLPswith respect to a bandwidth of 6, 7, or 8 MHz.

The baseband formatting block 11300 includes baseband packetconstruction blocks 3100, 3100-1, . . . , and 3100-n, baseband packetheader construction blocks 3200, 3200-1, . . . , and 3200-n, andbaseband packet scrambling blocks 3300, 3300-1, . . . , and 3300-n, asillustrated in FIG. 5A. In an M-PLP operation, the baseband formattingblock generates a plurality of PLPs as necessary.

The baseband packet construction blocks 3100, 3100-1, . . . , and 3100-nconstruct baseband packets. Each baseband packet 3500 includes a header3500-1 and a payload 3500-2 as illustrated in FIG. 5B. A baseband packetis fixed to a length Kpayload. ALP packets 3610 to 3650 are sequentiallymapped to a baseband packet 3500. When the ALP packets 3610 to 3650 donot completely fit in the baseband packet 3500, these packets aredistributed between a current baseband packet and a next basebandpacket. The ALP packets are distributed in a unit of a byte.

The baseband packet header construction blocks 3200, 3200-1, . . . , and3200-n construct a header 3500-1. The header 3500-1 includes threeparts, that is, a base field (also referred to as a base header) 3710,an optional field (also referred to as an option header) 3720, and anextension field (also referred to as an extension header) 3730, asillustrated in FIG. 5B. Herein, the base field 3710 is shown in everybaseband packet and the optional field 3720 and the extension field 3730may not be shown in every baseband packet.

A main function of the base field 3710 provides a pointer of an offsetvalue as bytes to indicate a start of a next ALP packet in a basebandpacket. When an ALP packet starts a baseband packet, the value of thepointer becomes 0. When there is no ALP packet that starts in thebaseband packet, the value of the pointer may be 8191 and a base headerof 2 bytes may be used.

The extension field 3730 may be used afterwards and for example, usedfor a baseband packet counter, baseband packet time stamping, additionalsignaling, and the like.

The baseband packet scrambling blocks 3300, 3300-1, . . . , and 3000-nscramble the baseband packet.

As in a case where payload data mapped to constellations includerepetitive sequences, the payload data is scrambled at all times beforedirection error correction encoding, so as not to be always mapped atthe same point.

FIG. 6 is a block diagram illustrating a configuration of a transmittingapparatus 600, according to an exemplary embodiment.

Referring to FIG. 6, the transmitting apparatus 600 includes an L1signaling generator 610, a frame generator 620, and a signal processor630.

The L1 signaling generator 610 generates L1 signaling. The L1 signalinggenerator 610 corresponds to a signaling unit 15000 illustrated in FIG.3B. Also, as described above, L1 signaling may be encoded through anadditional BICM encoder or the BCIM encoder which is for encoding datato be serviced. In particular, the L1 signaling includes a plurality ofPLPs included in a payload configuring a frame or information about adata symbol.

In detail, the L1 signaling generator 610 generates the L1 signalingincluding first information and second information.

Here, as described above, the L signaling includes information about theplurality of PLPs included in the payload configuring the frame orinformation about the data symbol, and may include L1 basic and L1detail.

Herein, the first information and the second information configuring theL1 signaling will be described as respectively corresponding to the L1basic and the L1 detail.

Also, the frame generator 620 generates a frame including a payloadincluding a plurality of sub frames. In detail, the frame includes abootstrap (BS), a preamble, and a payload. The BS includes informationfor processing an OFDM symbol included in the preamble, and the preambleincludes information for processing the OFDM symbol included in thepayload. Here, the frame generator 620 corresponds to aframing/interleaving block 13000 of FIG. 3B.

Also, the signal processor 630 includes the preamble including the L1signaling in the frame and then transmits the frame including thepreamble. Here, the signal processor 630 corresponds to a waveformgeneration block 14000 of FIG. 3B.

In detail, a configuration of the frame will now be described in detail.

FIG. 7 is a diagram illustrating a configuration of the frame 700 thatis a base for describing the present invention.

Referring to FIG. 7, the frame 700 may be represented as a combinationof three basic components. In detail, the frame 700 may include a BS 710located at a start part of each frame, a preamble 720 located next tothe BS 710, and a payload 730 located next to the preamble 720.

Here, the preamble 720 includes L1 signaling to be used for processingdata included in the payload 730.

Also, the payload 730 includes at least one sub frames 730-1, . . . ,and 730-n. If a plurality of sub frames exist in the payload 730, theplurality of sub frames are connected to one another to be arrangedbased on a time axis illustrated in FIG. 7.

Each of the sub frames 730-1, . . . , and 730-n has a Fast FourierTransform (FFT) size, a GI length, a scattered pilot pattern, and thenumber of effective carriers. The FFT size, the GI length, the scatteredpilot pattern, and the number of effective carriers are not changed inthe same sub frame. However, FFT sizes, GI lengths, scattered pilotpatterns, and the numbers of effective carriers may be different betweendifferent sub frames 730-1, . . . , and 730-n of the frame 700.

In particular, the BS 710 may include a sync symbol located at a startpart of each frame to detect signals, precisely synchronize the signalswith one another, estimate a frequency offset, and perform an initialchannel estimation.

Also, the BS 710 may include control signaling required for receivingand decoding the other parts (i.e., the preamble 720 and the payload730) excluding the BS 710 from the frame 700.

In detail, the BS 710 uses a fixed sampling rate of 6.144 Ms/sec and afixed bandwidth of 4.5 Mhz regardless of a channel bandwidth used forthe other parts except the BS 710.

The preamble 720 includes L basic 720-1 and L1 detail 720-2. In detail,the L1 basic 720-1 includes information about an FEC-type required fordecoding the L detail 720-2, the number of symbols included in thepreamble 720, a length of the L detail 720-2, and the like.

Also, the L1 detail 720-2 includes information about the number of subframes 730-1, . . . , and 730-n included in the payload 730, mod/cod(modulation/code rate) of symbols included in each of the sub frames730-1, . . . , and 730-n, and the like.

Here, the L1 basic 720-1 according to the exemplary embodiment includesinformation required for decoding a first sub frame among a plurality ofsub frames 730-1, . . . , and 730-n.

In contrast, the L1 detail 720-2 includes information required fordecoding the other sub frames except the first sub frame among theplurality of sub frames 730-1, . . . , and 730-n.

FIG. 8 is a diagram illustrating a configuration of the frame 700 ofFIG. 7 in detail.

Referring to FIG. 8, the frame 700 includes the BS 710, the preamble720, and a plurality of sub frames 730-1, 730-2, . . . configuring thepayload 730. The preamble 720 may include one L1 basic (L1B) 720-1 andone or more L details (LiD) 720-2, and each of the sub frames 730-1,730-2, . . . may include a plurality of data symbols 740.

Here, the L1 basic 720-1 includes information required for decoding thefirst sub frame 730-1 among the plurality of sub frames 730-1, 730-2, .. . .

For example, if the first sub frame 730-1 of the plurality of sub frames730-1, 730-2, . . . includes 10 data symbols from P0 to P9, and thesecond sub frame 730-2 includes 10 data symbols from P10 to P19, the L1basic 720-1 includes information required for decoding 10 data symbolsfrom P0 to P9.

Also, the L1 detail 720-2 includes information required for decoding theother sub frames 730-2, . . . except the first sub frames 730-1 amongthe plurality of sub frames 730-1, 730-2, . . . .

For example, if the first sub frame 730-1 among the plurality of subframes 730-1, 730-2, . . . includes 10 data symbols from P0 to P9, andthe second sub frame 730-2 includes 10 data symbols from P10 to P19, theL1 detail 720-2 includes information required for decoding 10 datasymbols from P10 to P19 included in the second sub frame 730-2 exceptthe first sub frame 730-1.

Even if a third sub frame, a fourth sub frame, or the like exists, theL1 detail 720-2 may include information required for decoding datasymbols included in the third sub frame, the fourth sub frame, or thelike.

As described above, the L1 signaling generator 610 of the transmittingapparatus 600 generates L1 signaling including the L1 basic 720-1including information required for decoding the first sub frame 730-1among a plurality of sub frames and the L detail 720-1 includinginformation required for decoding the other sub frames 730-2, . . .except the first sub frame 730-1 among the plurality of sub frames. Ifthe signal processor 630 includes a preamble including the L1 signalingin a frame, and then, transmits the preamble to a receiver, the receiveris capable of accelerating a start time for decoding a payload includedin the frame by using information required for decoding the first subframe 730-1 among a plurality of sub frames included in the L basic720-1. This will now be described in detail with reference to FIGS. 9and 10.

FIG. 9 is a diagram illustrating a start time for decoding a related artpayload.

Referring to FIG. 9, if a receiver receives a frame including a payloadincluding a BS 910, L basic (LB) 920, three L1 details (LDs) 930, 940,and 950, P1, P2, P3, P4, . . . , a time corresponding to 2 symbols (BSdecoding) is delayed to decode the BS 910 to detect information 910′ fordecoding the L1B 920 included in the BS 910; and a time corresponding to1 symbol (FFT) and 6 symbols (LB decoding), i.e., 7 symbols, is delayedto decode the L1B 920 to detect information 920′ for decoding the LDs930, 940, and 950.

Also, to respectively decode the LDs 930, 940, and 950 to detectinformation 930′, 940′, and 950′ for decoding payloads included in theLDs 930, 940, and 950, a time corresponding to approximately 6 symbols(first L1D decoding) is delayed to decode the first L1D 930, and a timecorresponding to approximately a total of 2 symbols (second L1D FFT andthird L1D FFT) is delayed to perform FFT with respect to the second L1D940 and the third L1D 950.

Thus, when a frame is received, a receiver may start decoding the firstdata symbol P0 960 after a time, corresponding to approximately 17symbols, which is a sum of a time corresponding to 2 symbols (BSdecoding) delayed to decode the BS 910 to detect information 910′ fordecoding the L1B 920 included in the BS 910, a time corresponding to 1symbol (FFT) and 6 symbols (L1 basic decoding) delayed to decode the L1B920 to detect information 920′ for decoding the L1Ds 930, 940, and 950included in the L1B 920, a time corresponding to 6 symbols (first L1Ddecoding) delayed for decoding the first L1D 930, and a timecorresponding to a total of 2 symbols (second L1D FFT and third L1D FFT)delayed for performing FFT with respect to the second L1D 940 and thethird L1D 950. Only when all of the L1Ds 930, 940, and 950 arecompletely decoded, P0 decoding 960′ may be completed based oninformation required for decoding the first data symbol P0 960.

Therefore, the receiver may be able to start decoding a first datasymbol included in a payload after a time corresponding to approximately17 symbols has passed from a time when the frame is received.

FIG. 10 is a diagram illustrating a start time for decoding a payloadaccording to an exemplary embodiment.

Referring to FIG. 10, a frame according to an exemplary embodiment, forexample, includes a payload including a BS 910, L1B 920, three L1Ds 930,940, and 950, a first sub frame 960 including a plurality of datasymbols P0 960-1, P1, P2, P3, P4, . . . , and P10 960-10, and a secondsub frame 970 including a plurality of data symbols P11, P12, P13, . . ., and P19.

Here, as described above, the L1B 920 includes information for decodingthe first sub frame 960. In detail, the L1B 920 includes information fordecoding P0 960-1, P1, P2, P3, P4, . . . , and P10 960-10 included inthe first sub frame 960.

Also, if such a frame is received by a receiver, a time corresponding to2 symbols (BS decoding) is delayed to decode the BS 910 to detectinformation 910′ for decoding the L1B 920 included in the BS 910, and atime corresponding to 1 symbol (FFT) and 6 symbols (L1B decoding), i.e.,7 symbols, is delayed to decode the L1B 920 to detect information 920′for decoding L1Ds 930, 940, and 950 included in the L1B 920 at thereceiver.

Here, the L1B 920 includes information for decoding the first sub frame960. Therefore, if decoding of the L1B 920 is completed, and thusinformation for decoding the first sub frame 960 included in the L1B 920is detected, the receiver according to an exemplary embodiment mayimmediately start decoding the first sub frame 960 without waiting aprocess of decoding the L1Ds 930, 940, and 950 has been finished. Thatis, the receiver may perform decoding of the first sub frame 960 withoutinformation included in the L1Ds 930, 940, and 950, and complete P0decoding 960-1′ as illustrated in FIG. 10.

As a result, referring to FIG. 10, after delaying a time, correspondingto 9 symbols, which is a sum of a time corresponding to 2 symbols (BSdecoding) delayed to detect information 910′ for decoding the L1B 920included in the BS 910, and a time corresponding to 1 symbol (FFT) and 6symbols (L1B decoding), i.e., 7 symbols, delayed to decode the L1B 920to detect information 920′ for decoding the L1Ds 930, 940, and 950included in the L1B 920 from a time when a frame is received, thereceiver according to the exemplary embodiment may start decoding thefirst sub frame 960.

Therefore, in comparison between FIGS. 9 and 10, the L1B 920 accordingto an exemplary embodiment may include information for decoding P0960-1, P1, P2, P3, P4, . . . , and P10 960-10 included in the first subframe 960 to reduce a delay by a time corresponding to 8 symbols incomparison with a start time for decoding a payload of the related art,thereby accelerating a start time for decoding a payload.

In other words, according to the exemplary embodiment, a start time fordecoding a payload may be accelerated by a time taken for performing FFTwith respect to the L1Ds 930, 940, and 950 and decoding the L1Ds 930,940, and 950.

Therefore, the receiver may reduce a processing delay of a receivedstream, reduce a capacity of a memory, and easily perform a fast changesuch as a channel change.

FIG. 11 is a diagram illustrating information included in L1 basicaccording to an exemplary embodiment.

Referring to FIG. 11, information included in the L1 basic isinformation for decoding a first sub frame. The information for decodingthe first sub frame may be information about an FFT size of the firstsub frame, a length of a guard interval, a Peak to Average Power Ratio(PAPR), a scattered pilot pattern, a boundary symbol index, the numberof OFDM symbols, the number of effective carriers, and a length of anadditional guard interval.

In detail, the information included in the L1 basic may be expressed asFIRST_SUB_FFT_SIZE, FIRST_SUB_GUARD_INTERVAL, FIRST_SUB_PAPR,FIRST_SUB_SP_PATTERN, FIRST_SUB_SBS_FIRST, FIRST_SUB_SBS_LAST,FIRST_SUB_OFDM_SYMBOL, FIRST_SUB_NOC, and FIRST_SUB_EXCESS_CP.

Here, FIRST_SUB_FFT_SIZE refers to the FFT size of the first sub frame,FIRST_SUB_GUARD_INTERVAL refers to the length of the guard intervalinserted into the first sub frame, FIRST_SUB_PAPR refers to the PAPR ofthe first sub frame, FIRST_SUB_SP_PATTERN refers to the scattered pilotpattern inserted into the first sub frame, FIRST_SUB_SBS_FIRST refers toa boundary symbol index inserted into a start end of the first subframe, FIRST_SUB_SBS_LAST refers to a boundary symbol index insertedinto a last end of the first sub frame, FIRST_SUB_OFDM_SYMBOL refers tothe number of OFDM symbols inserted into the first sub frame,FIRST_SUB_NOC refers to the number of effective carriers of the firstsub frame, and FIRST_SUB_EXCESS_CP refers to the length of theadditional guard interval inserted into the first sub frame.

FIG. 12 is a block diagram illustrating a configuration of a receivingapparatus 2000 according to an exemplary embodiment.

Referring to FIG. 12, the receiving apparatus 2000 includes a receiver2100 and a signal processor 2200.

The receiver 2100 receives a frame including a preamble including L1signaling including L1 basic and L1 detail and a payload including aplurality of sub frames. A detailed configuration of the frame has beendescribed with reference to FIG. 7, and thus a detailed descriptionthereof is omitted.

Also, the signal processor 2200 signal-processes the frame.

Here, the L1 basic may include information required for decoding a firstsub frame among the plurality of sub frames, and the signal processor2200 may decode the first sub frame based on the information included inthe L1 basic and decode the L1 detail in parallel.

In detail, as described above with reference to FIG. 10, the signalprocessor 2200 may start decoding the first sub frame 960 based on theinformation 920′ included in the L1B 920, decode the first sub frame960, and decode the L1Ds 930, 940, and 950 in parallel with the decodingof the first sub frame 960.

Also, the signal processor 2200 completes the decoding of the first subframe and then decodes the other sub frames except the first sub framebased on the decoded L1 detail.

For example, as described above with reference to FIG. 10, the signalprocessor 2200 may decode the first sub frame 960 based on theinformation 920′ included in the L1B 920 and decode the L1Ds 930, 940,and 950 in parallel with the decoding of the first sub frame 960. Justwhen the decoding of the first sub frame 960 is completed, the decodingof the L1Ds 930, 940, and 950 is completed. Therefore, after thedecoding of the first sub frame 960 is completed, the signal processor2200 may start decoding of the other sub frame 970.

Therefore, the signal processor 2200 according to the exemplaryembodiment may accelerate a decoding start time of a payload asdescribed above.

FIG. 13 is a block diagram provided to explain in detail a signalprocessor according to an exemplary embodiment.

Referring to FIG. 13, the signal processor 2200 includes a demodulator2210, a signal decoder 2220, and a stream generator 2230.

The demodulator 2210 performs demodulation according to OFDM parametersfrom received RF signals, performs sync-detection, and recognizeswhether a currently received frame includes necessary service data whenthe sync is detected from signaling information stored in a sync area.For example, the demodulator 831 may recognize whether a mobile framefor a mobile receiver is received or a fixed frame for a fixed receiveris received.

In this case, if OFDM parameters are not previously determined regardinga signaling area and a data area, the demodulator 2210 may performdemodulation by obtaining OFDM parameters regarding the signaling areaand the data area stored in the sync area, and obtaining informationabout OFDM parameters regarding the signaling area and the data areawhich are disposed right after the sync area.

The signal decoder 2220 performs decoding of necessary data. In thiscase, the signal decoder 2220 may perform decoding by obtainingparameters of an FEC method and a modulating method regarding the datastored in each data area based on the signaling information. Further,the signal decoder 2220 may calculate positions of necessary data basedon the data information included in a configurable field and a dynamicfield. Thus, it may calculate which positions of the frame a requestedPLP is transmitted.

The stream generator 2230 may generate data to be served by processing abaseband packet input from the signal decoder 2220.

For example, the stream generator 2230 may generate an ALP packet fromthe baseband packet in which errors are corrected based on an ISSY mode,buffer size (BUFS), time to output (TTO) values, and input stream clockreference (ISCR) values.

Specifically, the stream generator 2230 may include de-jitter buffers.The de-jitter buffers may regenerate correct timing to restore an outputstream based on the ISSY mode, BUFS, TTO values, and ISCR values.Thereby, a delay for sync between a plurality of PLPs may becompensated.

FIG. 14 is a block diagram of a receiving apparatus 4400 according to anexemplary embodiment.

Referring to FIG. 14, the receiving apparatus 4400 may include acontroller 4410, an RF receiver 4420, a demodulator 4430, and a serviceplayer 4440.

The controller 4410 determines an RF channel and a PLP in which aselected service is transmitted. At this process, the RF channel may bedefined by a center frequency and a bandwidth, and the PLP may bedefined by a PLP identifier (ID). Certain services may be transmittedthrough more than one PLP belonging to more than one RF channel percomponent constituting services. However, it is assumed in the followingdescriptions that all data required for playing one service istransmitted through one PLP with one RF channel for convenientexplanation. Thus, services are provided with a unique data obtainingpath to play services, and the data obtaining path is specified by an RFchannel and a PLP.

The RF receiver 4420 extracts RF signals from a selected RF channel bythe controller 4410, and delivers OFDM symbols, extracted by performingsignal-processing of the RF signals, to the demodulator 4430. The signalprocessing may include synchronization, channel estimation, andequalization. Information required for the signal-processing ispredetermined between a transmitting apparatus and the receivingapparatuses or transmitted to the receiving apparatus in a predeterminedOFDM symbols among the OFDM symbols.

The demodulator 4430 extracts a user packet by performingsignal-processing of the OFDM symbols, and delivers the user packet tothe service player 4440. The service player 4440 plays and outputs theservice selected by a user with the user packet. A format of the userpacket may be different according to implementing services. For example,a TS packet or an IPv4 packet may be the user packet.

FIG. 15 is a block diagram describing the demodulator 4430 of FIG. 14,according to an exemplary embodiment.

Referring to FIG. 15, the demodulator 4430 may include a frame demapper4431, a BICM decoder 4432 for L1 signaling, a controller 4433, a BICMdecoder 4434, and an output processor 4435.

The frame demapper 4431 selects OFDM cells constituting FEC blocksbelonging to a selected PLP from a frame constituted with OFDM symbolsbased on controlling information delivered from the controller 4433, anddelivers the OFDM cells to the decoder 4434. Further, the frame demapper4431 selects OFDM cells corresponding to more than one FEC blockincluded in the L signaling, and delivers the OFDM cells to BICM decoder4432 for the L signaling.

The BICM decoder 4432 for the L1 signaling signal-processes the OFDMcells corresponding to the FEC blocks belonging to the L1 signaling,extracts L1 signaling bits, and delivers the L1 signaling bits to thecontroller 4433. In this case, the signal-processing may includeextracting log-likelihood ratio (LLR) values for decoding low densityparity check (LDPC) codes in OFDM cells, and decoding the LDPC codes byusing the extracted LLR values.

The controller 4433 extracts an L1 signaling table from the L1 signalingbits, and controls operations of the frame demapper 4431, the BICMdecoder 4434, and the output processor 4435 by using values of the L1signaling table. FIG. 15 illustrates that the BICM decoder 4432 for theL1 signaling does not use controlling information of the controller 4433for convenient explanation. However, if the L1 signaling includes alayer structure similar to L pre-signaling and L1 post-signalingdescribed above, the BICM decoder 4432 for the L1 signaling may beconstituted with more than one BICM decoding block, and operations ofthe BICM decoding blocks and the frame demapper 4431 may be controlledbased on upper-layer L1 signaling information, as clearly understood inthe above description.

The BICM decoder 4434 signal-processes the OFDM cells constituting FECblocks belonging to the selected PLP, extracts baseband packets, anddelivers the baseband packets to the output processor 4435. Thesignal-processing may include extracting LLR values for coding anddecoding LDPC codes in OFDM cells, and decoding the LDPC codes by usingthe extracted LLR values. These two operations may be performed based onthe controlling information delivered from the controller 4433.

The output processor 4435 signal-processes the baseband packets,extracts a user packet, and delivers the extracted user packet to theservice player. In this case, the signal-processing may be performedbased on the controlling information delivered from the controller 4433.

According to an exemplary embodiment, the output processor 1235 mayinclude an ALP packet processor (not illustrated) which extracts an ALPpacket from a baseband packet.

FIG. 16 is a flowchart provided to briefly explain an operation of areceiving apparatus from a time point when a user selects a service to atime point when the selected service is played.

It is assumed that service information about all services that may beselected at an initial scan process of S4600 is obtained prior to aservice select process at S4610. The service information may includeinformation about an RF channel and a PLP which transmits data requiredfor playing a specific service in a current broadcasting system. Oneexample of the service information may be Program-SpecificInformation/Service Information (PSI/SI) of an MPEG-2 TS, which may beusually obtained through L2 signaling and upper layer signaling.

When a user selects a service at S4610, the receiving apparatus modifiesa frequency transmitting the selected service at S4620, and performsextracting RF signals at S4630. While performing S4620 modifying thefrequency transmitting the selected service, the service information maybe used.

When the RF signals are extracted, the receiver performs S4640extracting L1 signaling from the extracted RF signals. The receivingapparatus selects the PLP transmitting the selected service by using theextracted L1 signaling at S4650, and extracts baseband packets from theselected PLP at S4660. At S4650 selecting the PLP transmitting theselected service, the service information may be used.

Further, S4660 extracting the baseband packets may include selectingOFDM cells belonging to the PLP by demapping a transmission frame,extracting LLR values for coding/decoding LDPC, and decoding LDPC codesby using the extracted LLR values.

The receiving apparatus performs S4670 extracting an ALP packet from theextracted baseband packet by using header information about theextracted baseband packet, and performs S4680 extracting a user packetfrom the extracted ALP packet by using header information about theextracted baseband packet. The extracted user packet is used in S4690playing the selected service. At S4670 extracting the ALP packet and atS4680 extracting the user packet, L1 signaling information obtained atS4640 extracting the L1 signaling may be used. In this case, a processof extracting the user packet from the ALP packet (restoring null TSpacket and inserting a TS sync byte) is the same as described above.According to the exemplary embodiments as described above, various typesof data may be mapped to a transmittable physical layer, and dataprocessing efficiency may be improved.

FIG. 17 is a flowchart illustrating a method of controlling atransmitting apparatus, according to an exemplary embodiment.

Referring to FIG. 17, in operation S1710, L signaling including L1 basicand L detail is generated.

In operation S1720, a frame including a payload including a plurality ofsub frames is generated.

In operation S1730, a preamble including the L1 signaling is included inthe frame, and then the frame is transmitted.

Here, the L1 basic includes information for decoding a first sub frameof a plurality of sub frames.

Also, the L1 detail includes information for decoding the other subframes except the first sub frame.

The information for decoding the first sub frame includes informationabout an FFT size of the first sub frame, a length of a guard interval,a PAPR, a scattered pilot pattern, a boundary symbol index, the numberof OFDM symbols, the number of effective carriers, and a length of anadditional guard interval.

FIG. 18 is a flowchart illustrating a method of controlling a receivingapparatus, according to an exemplary embodiment.

Referring to FIG. 18, in operation S1810, the receiving apparatusreceives a frame including a preamble including L1 signaling includingL1 basic and L1 detail and a payload including a plurality of subframes.

In operation S1820, the receiving apparatus signal-processes the frame.

Here, the signal-processing operation decodes the first sub frame basedon the information included in the L1 basic and decodes the L1 detail inparallel with the decoding of the first sub frame.

Also, the method of controlling the receiving apparatus may furtherinclude completing the decoding of the first sub frame and then decodingthe other sub frames except the first sub frame based on the decoded L1detail.

There may be provided a non-transitory computer readable medium thatstores a program sequentially performing a signal processing method.

The non-transitory computer readable medium is a medium which does notstore data temporarily such as a register, cash, and memory but storesdata semi-permanently and is readable by devices. More specifically, theaforementioned applications or programs may be stored in thenon-transitory computer readable media such as compact disks (CDs),digital video disks (DVDs), hard disks, Blu-ray disks, universal serialbuses (USBs), memory cards, and read-only memory (ROM).

At least one of the components, elements, modules or units representedby a block as illustrated in FIGS. 2 and 6-12 may be embodied as variousnumbers of hardware, software and/or firmware structures that executerespective functions described above, according to an exemplaryembodiment. For example, at least one of these components, elements,modules or units may use a direct circuit structure, such as a memory, aprocessor, a logic circuit, a look-up table, etc. that may execute therespective functions through controls of one or more microprocessors orother control apparatuses. Also, at least one of these components,elements, modules or units may be specifically embodied by a module, aprogram, or a part of code, which contains one or more executableinstructions for performing specified logic functions, and executed byone or more microprocessors or other control apparatuses. Also, at leastone of these components, elements, modules or units may further includeor may be implemented by a processor such as a central processing unit(CPU) that performs the respective functions, a microprocessor, or thelike. Two or more of these components, elements, modules or units may becombined into one single component, element, module or unit whichperforms all operations or functions of the combined two or morecomponents, elements, modules or units. Also, at least part of functionsof at least one of these components, elements, modules or units may beperformed by another of these components, elements, modules or units.Further, although a bus is not illustrated in the above block diagrams,communication between the components, elements, modules or units may beperformed through the bus. Functional aspects of the above exemplaryembodiments may be implemented in algorithms that execute on one or moreprocessors. Furthermore, the components, elements, modules or unitsrepresented by a block or processing steps may employ any number ofrelated art techniques for electronics configuration, signal processingand/or control, data processing and the like.

The foregoing exemplary embodiments and advantages are merely exemplaryand are not to be construed as limiting the inventive concept. Theinventive concept can be readily applied to other types of apparatuses.Also, the description of the exemplary embodiments is intended to beillustrative, and not to limit the scope of the claims, and manyalternatives, modifications, and variations will be apparent to thoseskilled in the art.

What is claimed is:
 1. A receiving method comprising: receiving a framecomprising a bootstrap, a preamble and a payload through a channel;performing an initial channel estimation for the channel based on thebootstrap; performing an orthogonal frequency division multiplexing(OFDM) processing on the preamble and the payload, decoding the preambleand the payload, wherein the preamble comprises first signalinginformation and second signaling information, wherein the payloadcomprises at least one sub frame, wherein the first signalinginformation comprises information required to decode the secondsignaling information and information required for an initial processingof the OFDM processing of a first sub frame among the at least one subframe, wherein the second signaling information comprises informationfor a configuration of the at least one sub frame, and wherein the firstsignaling information is used to facilitate the initial processing ofthe first sub frame without waiting for decoding of the second signalinginformation.
 2. The receiving method of claim 1, wherein the bootstrapis located at a beginning of the frame, the preamble is locatedfollowing the bootstrap, and the payload is located following thepreamble.
 3. The receiving method of claim 1, wherein the informationrequired for the initial processing of the first sub frame comprisesinformation about a Fast Fourier Transform (FFT) size of the first subframe, a length of a guard interval, a Peak to Average Power Ratio(PAPR), a scattered pilot pattern, a boundary symbol index, a number ofOFDM symbols, a number of effective carriers, and a length of anadditional guard interval.